Dynamic Constitutive And Damage Parameters Of Ultra-high Strength Steel G31 At Different Tempering Temperatures

G31 steel is a kind of low alloy ultra-high strength steel.Because of its ultra-high strength characteristics and relatively easy access to materials,it is widely used in the field of military industry in high-strength structural parts.In this paper,the constitutive and failure model parameters of G31 steel with different tempering temperature are studied.Firstly,the mechanical properties of G31 steel with different tempering temperature under quasi-static,dynamic and high temperature conditions were studied.The constitutive model parameters and failure model parameters of G31 steel with different tempering temperature are obtained by fitting the mechanical test results,and the influence law of tempering temperature on each parameter is analyzed.The specific research contents of this paper are as follows:(1)The dynamic and static and high temperature mechanical properties of G31 steel with different tempering temperature were tested,including quasi-static compression test,high temperature compression test,split Hopkinson compression bar test,notch tensile test,quasistatic tensile test under different strain rates and high temperature tensile test.The mechanical properties of G31 steel with different tempering temperature under dynamic and static conditions and high temperature conditions were obtained.The influence of tempering temperature on the mechanical properties of G31 steel under dynamic and static conditions and high temperature conditions was analyzed.(2)The Johnson-Cook(J-C)constitutive model of G31 steel with different tempering temperature was studied.The quasi-static compression test results,high temperature compression test results and split Hopkinson bar test results were mainly used to fit the J-C constitutive model parameters of G31 steel with different tempering temperature,and the influence of tempering temperature on the J-C constitutive model parameters of G31 steel was studied.(3)The J-C failure model of G31 steel with different tempering temperature was studied.The results of notch tensile test,quasi-static tensile test under different strain rate and high temperature tensile test were used to fit the J-C failure model parameters of G31 steel with different tempering temperature,and the effect of tempering temperature on the J-C failure model parameters of G3 steel was studied.(4)The impact test of G31 steel with different tempering temperature was carried out.The impact test of G31 steel with different tempering temperature at different speed was carried out by using the impact test platform of Taylor bar.The influence of tempering temperature on the test results was analyzed.The reliability of J-C constitutive and failure model parameters of G31 steel with different tempering temperature was verified by numerical simulation.